Moorthy, Mv

Abstract Background Glycosylation, a key post-translational modification, plays a crucial role in biological pathways related to atherosclerosis. Purpose To investigate whether specific immunoglobulin G (IgG) N-glycosylation patterns are associated with premature myocardial infarction (MI) and to evaluate whether a glycan-based score improves case identification beyond traditional cardiovascular risk factors. Methods We measured 27 IgG N-glycans using capillary gel electrophoresis in 377 cases of premature first MI (men ≤55 years; women ≤65 years) and 377 controls matched for age (±5 years), sex, and nationality from the Gulf PREVENT study, a case-control study investigating risk factors for premature MI in the United Arab Emirates. We performed conditional logistic regression to evaluate associations between IgG N-glycans and premature MI, adjusting for age, body mass index, LDL-C, HDL-C, hs-CRP, hypertension, diabetes, and smoking. Using LASSO regression, we derived a novel IgG glycan score as a linear combination of selected glycans associated with premature MI. We evaluated model performance using likelihood ratio tests and the area under the curve (AUC) adapted for the case-control design, using 10-fold cross-validation. Results After adjusting for cardiovascular risk factors, glycan peaks (P) 4, 13, 23, and 27 were positively associated with premature MI (false discovery rate [FDR]<0.05). Bisecting N-acetylglucosamine (GlcNAc) was the consistent glycosylation pattern among these four glycans. In contrast, P 22, a core-fucosylated and monogalactosylated glycan, had inverse association (FDR=0.02) with premature MI. An IgG glycan score, composed of Ps 2, 4, 8, 17, 20, and 24, was associated with twofold increase in premature MI risk per standard deviation increment (aOR,1.98 [95%CI,1.56–2.52]; P<0.001) after adjusting for cardiovascular risk factors. Further, the IgG glycan score significantly improved model fit and performance, as indicated by a significant improvement in the likelihood ratio test and AUC (P<0.001). Conclusion We identified novel IgG N-glycosylation patterns that were associated with premature MI independent of cardiovascular risk factors. Glycans enriched with bisecting GlcNAc had increased risk, while core fucosylation and monogalactosylation had decreased risk. A novel IgG glycan score had 2-fold increased risk of premature MI independent of other risk factors and improved model performance. These findings highlight the potential of IgG N-glycans as biomarkers and therapeutic targets for premature MI.